| Andrew Christian | Hollywood | 2001 |
| Anduril Industries | California | 2017 |
| Aniplex of America | Santa Monica | 2005 |
| Anthropic | San Francisco | January 26, 2021 |
| APC by Schneider Electric | West Kingston | 1981 |
| Apollo Computer | Chelmsford | 1980 |
| Apollo Group | Phoenix | 1973 |
| Apple Inc. | Cupertino | April 1, 1976 |
| Applied Materials | Santa Clara | 1967 |
| Aramark | Philadelphia | 1959 |
| Arby's | Sandy Springs | 1964 |
| ARCO | Los Angeles | 1966 |
| ArenaNet | Bellevue | 2000 |
| ARP Instruments, Inc. | United States | 1969 |
| Ashland Inc. | Covington | 1924 |
| AST Research | Irvine | 1980 |
| Atari Corporation | Sunnyvale | July 2, 1984 |
| Au Bon Pain | Boston | 1978 |
| Auburn Automobile | Auburn | 1900 |
| Automatic Data Processing | Roseland | 1949 |
| AutoNation | Fort Lauderdale | 1996 |
| Avis Budget Group | Parsippany-Troy Hills | 2006 |
| Avnet | Phoenix | 1921 |
| Axios | Arlington County | 2017 |
| Babcock & Wilcox | Charlotte, United States, New York City | 1867 |
| Baker Hughes | Houston | 1987 |
| Baker Motor Vehicle | Cleveland | 1899 |
| Baldwin Piano Company | Trumann | 1862 |
| Banana Republic | San Francisco | 1978 |
| Basecamp | Chicago | 2004 |
| Baskin-Robbins | Canton | 1945 |
| Bausch & Lomb | Vaughan, Rochester | 1853 |
| Be Inc. | Menlo Park | 1990 |
| BEA Systems | San Jose | 1995 |
| Beatport | — | 2004 |
| Bechtel | Reston | 1906 |
| Bell & Howell | Wheeling | 1907 |
| Benchmark | Menlo Park | 1995 |
| Bendix Corporation | — | 1924 |
| Bergdorf Goodman | New York City | 1929 |
| Bethlehem Steel | Bethlehem | 1857 |
| BFG Technologies | Lake Forest | 2002 |
| Bicycle Playing Cards | Erlanger | — |
| Big Boy Restaurants | Warren | 1936 |
| Bigelow Aerospace | North Las Vegas | 1999 |
| Biogen | Cambridge | 1978 |
| Bitly | New York City | 2008 |
| Blackboard | Washington, D.C. | 1997 |